Minimal invasive aortic valve replacement surgery is associated with improved survival: a propensity-matched comparison

Abstract

Objectives: To compare early and long-term outcomes of minimally invasive surgery (MIS) versus full sternotomy (FS) isolated aortic valve replacement (AVR).

Methods: We retrospectively analysed all patients who underwent isolated bioprosthetic AVR between 2003 and March 2012 at our institution. Matching was performed based on a propensity score, which was obtained using the output of a logistic regression on relevant preoperative risk factors. Mean follow-up was 3.1±2.7 years (range 0-9.0 years) and was 99.8% complete.

Results: A total of 2051 patients (FS, 1572; MIS, 479) underwent isolated bioprosthetic AVR during the study period. MIS patients were significantly younger (67.8±11.2 vs 70.4±9.4 years) and had a lower logistic EuroSCORE (6.6±6.4 vs 11.2±13.4%, both P<0.001). Propensity matching resulted in 477 matched patients from each group, with no significant differences in any of the preoperative variables. Aortic cross-clamp times were significantly longer in MIS patients (59.4±16.0 vs 56.9±14.6 min, P=0.008). Nonetheless, MIS AVR was associated with a significantly lower incidence of intra-aortic balloon pump usage (0.4 vs 2.1%, P=0.042) and in-hospital mortality (0.4 vs 2.3%, P=0.013), while FS patients had a lower rate of re-exploration for bleeding (1.5 vs 4.2%, P=0.019). Five- and 8-year survival post-AVR was significantly higher in MIS patients (89.3±2.4% and 77.7±4.7% vs 81.8±2.2% and 72.8±3.1%, respectively, P=0.034). Cox regression analysis revealed MIS (hazard ratio: 0.47, 95% confidence interval: 0.26-0.87) as an independent predictor of long-term survival.

Conclusion: MIS AVR is associated with very good early and long-term survival, despite longer myocardial ischaemic times. MIS AVR can be performed safely with results that are at least equivalent to those achieved through an FS.

Keywords: Aortic valve replacement; Minimally invasive.